Question

How does Avogadro's law explain Gay-Lussac's law of combining volumes?

Answer 1

According to Avogadro's law under the same conditions of temperature and pressure, equal volumes of different gases have the same number of molecules.

since substances react in a simple ratio by a number of molecules, volumes of the gaseous reactants and products will also bear a simple ratio to one another.

Example:-

According to Gay-Lussac's Law

${\mathrm{H}}_2+{\mathrm{Cl}}_2\to 2\mathrm{HCl}$

$1V$ $1V$ $2V$

According to Avogadro's law

${\mathrm{H}}_2+{\mathrm{Cl}}_2\to 2\mathrm{HCl}$

$nmolecules$ $nmolecules$ $2nmolecules$